Electric time-switch.



E. STEIGER.

ELECTRIC TIME SWITCH. APPLICATION FILED APR-22, 1916.

1 ,292,122. Patented Jan. 21, 1919.

2 SHEETS-SHEET I.

E. STEIGER.

ELECTRIC TIME SWITCH. APPLICATION FILED APR. 22. 1916.

1,292.1 22. Patented Jan. 21,1919.

2 SHEETSSHEET 2.

EUGEN STEIGER, 0F ZURICH, SWITZERLAND.

ELECTRIC TIME-SWITCH.

Specificationcf Letters Patent.

' Patented Jan. 21, 1919.

Application filed Apri122, 1916. Serial No. 92,960.

To all whom it may concern:

Be it known that I, EIIGEN STEIGER, a citizen of the Swiss Confederation, and residing at Zurich, Switzerland, have invented certain new and useful Improvements in Electric Time-Switches, of which the following is a specification.

The present invention has reference to improvements in time switches, such as are used for automatically completing or breaking a light circuit, and it relates more particularly toa switch for this purpose which is operated automatically on the day light changing into twilight and vice versa, and the invention essentially resides in the construction, arrangement and cooperation of parts, as will hereinafter be fully described.

The time switches now extensively used for switching on and oil the lights in the controlled circuit are almost exclusively of the clock type, operate mechanically always at a predetermined, set time, and must be reset for operating at any other time. In the case of staircase or street illumination with such automatic control the caretaker thus, to be on the safe side, is apt to set the time ahead of actual necessity, causing thereby undue waste of current and lamp material; and, furthermore, such time clocks do not out the lamps in or out on a passing darkening, as would occur for instance dur ing a thunderstorm; and as far as I am aware, time switches are not at all used in railroad service, where they could be employed to good advantage, especially on lines running through tunnels.

My improved twilight switch effectively does away with these and other drawbacks and operates promptly at any time the atmospheric light conditions render the lighting up or extinguishing of the controlled lamps necessary or advisable, and I will now describe its detailed construction and operation with reference to the accompanying drawing, in which are shown diagrammatical views of two modifications, Figure 1 representing a switch for stationary operation on alternating current, and Fig. 2 a switch for mobile continuous current operation.

Referring first to Fig. 1, WH denotes the alternating current mains leading to a transformer Tr, 4 and volts. The 30 volt circuit is indicated by W, and the 4 volt circuit by W, W and W". The circuit W includes the (30118 a of a permanent horseshoe magnet a and a selenium cell 8, arranged in series.

In front of the poles of the magnet is arranged a sheet iron diaphragm b, as in a telephone, to which for the purpose of enhancing the oscillations a permanent horseshoe magnet c is fixed, the oles of the two magnets being oppositely disposed. 'From the magnet 0 extends a rod d, to the further end of which an insulator e is attached, which carries two insulated conducting arms 6 e These latter are connected to the line W and oscillate with the insulator e between two .pairs of contacts f f ,7, f Contact 7 is connected withcontact f and contact 7 with contact f. This arrangement A is on the one hand a secondary circuit relay, and on the other hand a current rectifier, inasmuch as by the crosswise grouping of the contact connections the alternating current is sent over the line G in always the same direction through the solenoids 9 g of the polarized relay B. The double-armed oscillating beam h, which supports the solenoid armatures k h is provided with a two-contact arm 72 which is normally pressed against the contact 2'' by the action of the draw-spring h which lat ter also withdraws the armatures from out of the solenoids, while they are drawn into the latter by the solenoids and the arm 72, is laid over against contact 71 when a sufiiciently strong current excites the solenoids g 9 This two contact arrangement alternatively closes the circuits VV W of a switch relay C. The armature 7a of this re lay is influenced by a spring t and by the electromagnet m, so that when no current is passing through the electromagnet the one end of the armature contacts with a contact spring at and also with a contact terminal 9 of a circuit FS, which includes a suitable switch D which serves to control the lightwhich is tapped for lnstance for ing system which is shown in the drawing as comprising lamps L. This circuit FS is also in continuous operative connection with the armature is at 9 In the position shown in the drawing the circuit W is closed for operation except at the break at 2' The armature k at the opposite end carries an insulated conducting lever is, to the free end of which is secured the insulating nose 70 The armature Z, is influenced by the electromagnet p and the spring 0 and carries at its upper end a catch Z adapted to lockingly cooperate with the insulated nose [0 of lever arm 70 In the relative position of the armatures 7c and Z shown, the circuit W would be interrupted at k Z In Fig. 2 GH indicates the direct current mains, of for instance 30 volts, by which coils 1- of a permanent horseshoe magnet 2 and a selenium cell S are served, as de scribed with reference to Fig. 1. In front of b is attracted by the magnet a or is repulsed with the changing direction of current in the coils at. These oscillations are intensified by the magnet c, which is necessary as owing to the high resistance of selenium cell i up to100,000 ohms) only very low currents a few milliamperes) flow through the coils. Relatively higher currents cannot be used without injury to the cell. If now the light striking the cell brightens up, the cell resistance diminishes and more current can pass through the coils; on dimming of the light the passage of current is correspondingly reduced, and the diaphragm, in keeping therewith, will oscillate to a greater or lesser extent. In the former instance the contact between e 6 and f f F, f will be of longer duration and more forcible than on lesser oscillations of the membrane. A correspondingly varying amount of current will then flow through the circuits W and G, which in turn excites the solenoids 1 g (relay B) more or less strongly, with the result that their armatures h k are drawn more or less deeply into the solenoids, the contact beam k then contacting either at i or at 6 for respectively closing the circuits W or W Thus the circuit W is closed by stronger, and the circuit W by weaker illumination of the selenium cell. When the former circuit is closed the armature k ofthe electromagnet m of relay C is attracted, cmrta ct between 9 and n is interrupted, and

catch Z lockingly contacts with the armature r lever Upon the circuit W being closed, the armature Z is attracted, the armature lever k is electrically disconnected from the catch P, the armature beam is swings around and contacts with the contact spring a, and contact is made at g for closing the circuit FS. v

-The operation of the arrangement according to Fig. 2 is the following :Upon the selenium cell S being strongly illuminated, more current will pass through the coils 1, the diaphragm is repulsed by the magnet 2 and the contactor beam 5 is pressed home on the contact 7, with the result that the relay C is operated to interrupt the switch circuit at g while on weaker illumination contact is made at 6 for closing the switch circuit FS at g.

The use of a diaphragm relay is of great importance, since such a relay responds readily to very weak currents and current fluctuations. In the direct current system even rather violent contrasts are compensated for, the twilight switch device, though exceedingly sensitive, being highly insensible to shocks and jars, since the stifl iron diaphragm, which is under continuous magnetic stress, is not readily influenced by being jarred.

What I claim is 1. An electric twilight switch comprising in combination, an electric circuit, a lightsensitive cell in said circuit and controlling the current of said circuit, polarized electromagnets in said circuit and excited by said current, a diaphragm actuated by said electro-magnets, a contact device connected to and operated by said diaphragm and switch relay circuits controlled by said contact device for the hereinbefore specified purpose.

2. An electric twilight switch comprising in combination an electric circuit, a lightsensitive cell in said circuit and controlling the current of said circuit, polarized electromagnets in said circuit and excited by said current, a diaphragm actuated by said electro-magnets, a. magnet secured to and vibrating with said diaphragm, a contact device operated by said diaphragm and switch relay circuits controlled by said contact device for the hereinbe'fore specified purpose.

3. An electric twilight switch comprising in combination, an electric circuit, a lightsensitive cell in said circuit and controlling the current of said circuit, polarized electromagnets in said circuit and excited by said current, a diaphragm actuated by said electro-magnets, a contact device in the form of a curent rectifier connected to and operated by said diaphragm and switch relay circuits controlled by said contact device for the hereinbefore specified purpose.

4. An electric twilight switch comprising in combination an electric circuit, a lightsensitive cell in said circuit and controlling the current of said circuit, polarized electromagnets in said circuit and excited by said current, a diaphragm actuated by said electromagnets, a contact device connected to and operated by said diaphragm, and two switch relay circuits alternately closed by said contact device, for the hereinbefore specified purpose.

In testimony whereof I aflix my signature in presence of two witnesses.

- EUGEN STEIGER. Witnesses:

CARL G'UBLER,

Bram C. GROB. 

